//
//  main.c
//  4.1.1
//
//  Created by apple on 2016/10/24.
//  Copyright © 2016年 apple. All rights reserved.
//

#include <stdio.h>
unsigned long Factorial(int n);
int main()
{
    int i;
    unsigned long f;
    unsigned long s=0;
    for(i=1;i<=5;i++)
    {
        f=Factorial(i);
        s=s+f*f;
    }
    printf("s=%lu\n",s);
    return 0;
    
}
unsigned long Factorial(int n)
{
    unsigned long t=1;
    int i;
    for (i=1;i<=n;i++)
        t=t*i;
        return t;
}